This depends on where you are at right now in the timeline of starting your business. If you are going to start a business and have yet to register a domain name, then I would say go ahead and register a domain name with the keywords you want in it. If you have multiple keywords then separate them with a hyphen. Also keep this simple, and make sure people can remember it. A site like http://www.this-is-my-main-keyword-and-here-is-another.com is probably not a good idea. The reason I say that it is a good idea is because when people link to you naturally, it is possible they will use your domain as the anchor text of the link. By having your keywords separated by hyphens in your domain, you assure yourself that any natural link you get will have the keywords that you want in the anchor text.
Filed under SEO by Brent Sweet